src: check size of args before using for exec_path

awilfox · RafaelGSS · commit 27d3201502df · 2023-01-05T13:11:34.000-03:00
If we are in an artifically created Environment that has no args set, and uv_exepath returns an error (for instance, if /proc is not mounted on a Linux system), then we crash with a nullptr deref attempting to use argv[0]. Fixes: #45901 PR-URL: #45902 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
diff --git a/src/env.cc b/src/env.cc
@@ -619,7 +619,7 @@ std::string GetExecPath(const std::vector<std::string>& argv) {
   std::string exec_path;
   if (uv_exepath(exec_path_buf, &exec_path_len) == 0) {
     exec_path = std::string(exec_path_buf, exec_path_len);
-  } else {
+  } else if (argv.size() > 0) {
     exec_path = argv[0];
   }
 

Original file line number	Diff line number	Diff line change
`@@ -619,7 +619,7 @@ std::string GetExecPath(const std::vector<std::string>& argv) {`
`619`	`619`	`std::string exec_path;`
`620`	`620`	`if (uv_exepath(exec_path_buf, &exec_path_len) == 0) {`
`621`	`621`	`exec_path = std::string(exec_path_buf, exec_path_len);`
`622`		`- } else {`
	`622`	`+ } else if (argv.size() > 0) {`
`623`	`623`	`exec_path = argv[0];`
`624`	`624`	`}`
`625`	`625`